But does it really matter that the most common grade is an A? Consider, say, a situation where there is a “triangular” distribution of grades: 5 A, 4 B, 3 C, 2 D, and 1 F. The most common grade is an A, but the median is a B (and the mean is 2.67 on a 4.0 scale, a B-minus). If there are more grade categories the same thing happens – if we have a triangular distribution of grades such as this, the median grade of the way up — about midway between a B-minus and a B on the 4.0 scale usual in the US. The mean grade would be of the way up the scale. More generally, say grades are in the interval [0, 1]. If grades are beta-distributed with parameters 1 and (my triangular idea is just the Beta(1, 2) distribution) then the modal grade will be 1 but the mean and median will be a good bit lower, and respectively.

(I’m not claiming that grades are beta-distributed, but that’s not a bad model for something that’s often thought of as being roughly normally distributed but has to be contained within an interval.)

Note that I didn’t write the headline for that article, which goes farther than the article itself does. Ten years later, I stand by what I wrote there, but would add that I _do_ think it’s a problem if grades are systematically awarded differently in different disciplines; it is bad if the decision whether to major in engineering in economics is affected by “I want to go to law school so need an A average so have to major in economics.”

Exactly why it’s not of any particular interest that the most popular vehicle is the Ford F-Series.

Note that I didn’t write the headline for that article, which goes farther than the article itself does. Ten years later, I stand by what I wrote there, but would add that I _do_ think it’s a problem if grades are systematically awarded differently in different disciplines; it is bad if the decision whether to major in engineering in economics is affected by “I want to go to law school so need an A average so have to major in economics.”